Scientific Name: Adelges tsugae Length: 0.8 mm Color: Brownish- reddish or black Shape:oval shaped
The hemlock Woolly Adelgid, is a fluid-feeding insect that feeds on hemlock trees throughout eastern North America. These insects were first brought down from Asia.Even though Woolly Adelgids are extremely small they are noticed by the cotton like eggs left on the leaves of hemlock tees.the cotton covered eggs start of as a brownish- orange and as the mature the color becomes darker. When the eggs hatch the Adelgids are a brownish or reddish color until finally black (1).
Detailed Description
The only thing that a Hemlock Woolly Adelgid really needs to survive are the hemlock trees. Using their stylet, thread-like mouth parts, they suck the sap out of the trees and inject toxins(1).
The Hemlock Woolly Adgid completes two generations per year on a hemlock and usually reproduce during the autumn and winter. From fall to spring they develop and mature to adults and prepare for reproduction once again. Even though there isn't much to a HWA, they usually don't last long if they don't lay eggs. in order to lay eggs one must find a mate, which means it must leave the Hemlock. If a Woolly Adelgid is away form a hemlock tree for too long it wont survive but if it stays there and wont find a mate it will die as well(2).
If the hemlock trees are not taken care of the Woolly Adelgids compete with them by feeding on them and within a year to four years the trees are dead(1).
An adult
Wolly Adelgid Eggs
Habitat and distribution
These insects were brought to the U.S. from Asia. The Hemlock Woolly Adelgids are very popular in japan and most part of Asia(4). These insects will be found mostly on the leaves of Hemlock trees.Most of them will be found in areas with a lot of nature and trees, such as Pennsylvania.
infestation in 2007( brown- infested, green- infested in 07)
Impact
The Woolly Adelgid doesn't have many positive impacts on the environment except that it is on the food chain for ladybugs(2).
an infested Hemlock
As for the negative affects, there are plenty. One of which they destroy the Hemlock trees which is home to some species. That ruins the forest and the environment.such trees attract insects to it and weaken the ecosystem. It is also a danger to have an unhealthy tree around, since it is so weak a strong wind could easily bring it down(1).
With that comes some health risks for humans as well. When there is a diseased or unhealthy tree it will collect different insects which will bring them close to humans and can be harmful(1).
Hemlock trees are also used for different purposes such as decoration and for building structures. Therefor if the tree dies it can not be used for either and if the Woolly Adelgids lay eggs in them then the tree will decrease in value causing economy losses(1).
History
The Woolly Adelgids first arrived in the U.S. by accident through a shipment from Asia. It began spreading in Richmond, Virginia in 1951. By 2005, it was established in portions of 16 States from Maine to Georgia. the most sever impact was found in Virginia, New Jersey, Pennsylvania, and Connecticut(5).
Control Measures
The Hemlock Woolly Adelgids are spreading rapidly and must be stopped in order to save our environment. Some ways to do this is...
-Infested trees can be selectively removed to prevent further spread(2) -they can also be mechanically removed from infested trees by spraying with water(1)
-clipping off the infested twigs and needles(1)
-Chemical insecticides can be applied to kill HWA such as horticultural oil or insecticidal soap(1)
Hemlock Woolly Adelgid
Woolly Adelgid eggs
General Information
Scientific Name: Adelges tsugae
Length: 0.8 mm
Color: Brownish- reddish or black
Shape:oval shaped
The hemlock Woolly Adelgid, is a fluid-feeding insect that feeds on hemlock trees throughout eastern North America. These insects were first brought down from Asia.Even though Woolly Adelgids are extremely small they are noticed by the cotton like eggs left on the leaves of hemlock tees.the cotton covered eggs start of as a brownish- orange and as the mature the color becomes da rker. When the eggs hatch the Adelgids are a brownish or reddish color until finally black (1).
Detailed Description
The only thing that a Hemlock Woolly Adelgid really needs to survive are the hemlock trees. Using their stylet, thread-like mouth parts, they suck the sap out of the trees and inject toxins(1).
The Hemlock Woolly Adgid completes two generations per year on a hemlock and usually reproduce during the autumn and winter. From fall to spring they develop and mature to adults and prepare for reproduction once again. Even though there isn't much to a HWA, they usually don't last long if they don't lay eggs. in order to lay eggs one must find a mate, which means it must leave the Hemlock. If a Woolly Adelgid is away form a hemlock tree for too long it wont survive but if it stays there and wont find a mate it will die as well(2).
If the hemlock trees are not taken care of the Woolly Adelgids compete with them by feeding on them and within a year to four years the trees are dead(1).Habitat and distribution
These insects were brought to the U.S. from Asia. The Hemlock Woolly Adelgids are very popular in japan and most part of Asia(4). These insects will be found mostly on the leaves of Hemlock trees.Most of them will be found in areas with a lot of nature and trees, such as Pennsylvania.Impact
The Woolly Adelgid doesn't have many positive impacts on the environment except that it is on the food chain for ladybugs(2).
As for the negative affects, there are plenty. One of which they destroy the Hemlock trees which is home to some species. That ruins the forest and the environment.such trees attract insects to it and weaken the ecosystem. It is also a danger to have an unhealthy tree around, since it is so weak a strong wind could easily bring it down(1).
With that comes some health risks for humans as well. When there is a diseased or unhealthy tree it will collect different insects which will bring them close to humans and can be harmful(1).
Hemlock trees are also used for different purposes such as decoration and for building structures. Therefor if the tree dies it can not be used for either and if the Woolly Adelgids lay eggs in them then the tree will decrease in value causing economy losses(1).
History
The Woolly Adelgids first arrived in the U.S. by accident through a shipment from Asia. It began spreading in Richmond, Virginia in 1951. By 2005, it was established in portions of 16 States from Maine to Georgia. the most sever impact was found in Virginia, New Jersey, Pennsylvania, and Connecticut(5).
Control Measures
The Hemlock Woolly Adelgids are spreading rapidly and must be stopped in order to save our environment. Some ways to do this is...
-Infested trees can be selectively removed to prevent further spread(2)
-they can also be mechanically removed from infested trees by spraying with water(1)
-clipping off the infested twigs and needles(1)
-Chemical insecticides can be applied to kill HWA such as horticultural oil or insecticidal soap(1)
Works Cited
1. "Big South Fork National River & Recreation Area." Oh, Ranger. 2008. 20 Nov.
2008 <http://www.ohranger.com/big-south-fork-river/plants>.
2. Chowdhury, Shahrina. "Hemlock Woolly Adelgid (Adelges tsugae)." Introduced
Species Summary Project Hemlock Woolly Adelgid (Adelges tsugae). 18 Nov.
2002. 10 Nov. 2008 <http://www.columbia.edu/itc/cerc/danoff-burg/
invasion_bio/inv_spp_summ/Adelges_tsugae.html>.
3. "Hemlock Wooly Adelgid." National Agricultural Library. 17 Nov. 2008. 20 Nov.
2008 <http://www.invasivespeciesinfo.gov/animals/hwa.shtml>.
4. McClure, Mark S. "Hemlock Woolly Adelgid." Green Share Factsheet. 1991. 20 Nov.
2008 <http://www.uri.edu/ce/factsheets/sheets/hemadelgid.html>.
5. "Pest Alert." Hemlock Woolly Adelgid. Aug. 2005. 20 Nov. 2008
<http://na.fs.fed.us/spfo/pubs/pest_al/hemlock/hwa05.htm>.
Discussion Post
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